Clay Engine: Edit mesh overlays

Based on the previous overlay shader from merwin.
This shader takes care of clipped vertex cases and do all edit mode face info in one pass (except face centers).
As the shading is done one the triangle itself the visual can't go beyond the surface of the mesh. That leads to half displayed edges on the outline of the mesh.
This problem can be fixed by a second pass.

This is work in progress.

1 files changed, 22 insertions, 1 deletions

diff --git a/source/blender/draw/modes/edit_mesh_mode.c b/source/blender/draw/modes/edit_mesh_mode.c
index d2299158e44..d894cbbe870 100644
--- a/source/blender/draw/modes/edit_mesh_mode.c
+++ b/source/blender/draw/modes/edit_mesh_mode.c
@@ -26,6 +26,8 @@
 #include "DRW_engine.h"
 #include "DRW_render.h"
 
+#include "GPU_shader.h"
+
 #include "draw_mode_pass.h"
 
 #include "edit_mesh_mode.h"
@@ -36,22 +38,33 @@ typedef struct EDIT_MESH_PassList {
 	struct DRWPass *ob_center_pass;
 	struct DRWPass *wire_outline_pass;
 	struct DRWPass *depth_pass_hidden_wire;
+	struct DRWPass *edit_face_overlay_pass;
 } EDIT_MESH_PassList;
 
 static DRWShadingGroup *depth_shgrp_hidden_wire;
+static DRWShadingGroup *face_overlay_shgrp;
 
 void EDIT_MESH_cache_init(void)
 {
 	EDIT_MESH_PassList *psl = DRW_mode_pass_list_get();
 	static struct GPUShader *depth_sh;
+	static struct GPUShader *overlay_sh;
 
 	if (!depth_sh) {
 		depth_sh = DRW_shader_create_3D_depth_only();
 	}
 
+	if (!overlay_sh) {
+		overlay_sh = GPU_shader_get_builtin_shader(GPU_SHADER_EDGES_OVERLAY_EDIT);
+	}
+
 	psl->depth_pass_hidden_wire = DRW_pass_create("Depth Pass Hidden Wire", DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS | DRW_STATE_CULL_BACK);
 	depth_shgrp_hidden_wire = DRW_shgroup_create(depth_sh, psl->depth_pass_hidden_wire);
 
+	psl->edit_face_overlay_pass = DRW_pass_create("Edit Mesh Face Overlay Pass", DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_LESS | DRW_STATE_BLEND);
+	face_overlay_shgrp = DRW_shgroup_create(overlay_sh, psl->edit_face_overlay_pass);
+	DRW_shgroup_uniform_vec2(face_overlay_shgrp, "viewportSize", DRW_viewport_size_get(), 1);
+
 	DRW_mode_passes_setup(NULL,
 	                      NULL,
 	                      &psl->wire_outline_pass,
@@ -63,7 +76,10 @@ void EDIT_MESH_cache_init(void)
 
 void EDIT_MESH_cache_populate(Object *ob)
 {
-	struct Batch *geom;
+	struct Batch *geom, *geom_overlay;
+	const struct bContext *C = DRW_get_context();
+	Scene *scene = CTX_data_scene(C);
+	Object *obedit = scene->obedit;
 
 	CollectionEngineSettings *ces_mode_ed = BKE_object_collection_engine_get(ob, COLLECTION_MODE_EDIT, "");
 	bool do_occlude_wire = BKE_collection_engine_property_value_get_bool(ces_mode_ed, "show_occlude_wire");
@@ -71,6 +87,10 @@ void EDIT_MESH_cache_populate(Object *ob)
 	switch (ob->type) {
 		case OB_MESH:
 			geom = DRW_cache_surface_get(ob);
+			if (ob == obedit) {
+				geom_overlay = DRW_cache_wire_overlay_get(ob);
+				DRW_shgroup_call_add(face_overlay_shgrp, geom_overlay, ob->obmat);
+			}
 			if (do_occlude_wire) {
 				DRW_shgroup_call_add(depth_shgrp_hidden_wire, geom, ob->obmat);
 				DRW_shgroup_wire_outline(ob, true, false, true);
@@ -107,6 +127,7 @@ void EDIT_MESH_draw(void)
 	EDIT_MESH_PassList *psl = DRW_mode_pass_list_get();
 
 	DRW_draw_pass(psl->depth_pass_hidden_wire);
+	DRW_draw_pass(psl->edit_face_overlay_pass);
 	DRW_draw_pass(psl->wire_outline_pass);
 	DRW_draw_pass(psl->non_meshes_pass);
 	DRW_draw_pass(psl->ob_center_pass);